Focusing device for electric lamps.



H. H. HOLLAND &1. C. STEARNS. Focusmc DEvscE FOR ELECTRIC LAMPS.

APPLICATION FILED AUG. 22. 1914.

Patented Apr. 27, 1915.

per c/C YS A'orney's HARRY H. HOLLAND AND'JASON C. STEARNS, OF WORCESTER, MASSACHUSETTS; SAID HOLLAND ASSIGNOR T0 SAID STEARNS.

FCUS'ING DEVICE FOR ELECTRIC LAMPS.

Specication of Letters Patent.

Patented Apr. 27, 1915.

Application filed August 22, 1914. Serial No. 857,997.

T0 all who-m it may concer-n Be it known that we, HARRY H. HOLLAND and JASON C. Srniniis, citizens of the United States, residing at VVoicester, in the county of Worcester and State of Massachusetts, have invented a new and useful Focusing Device for Electric Lamps.7 of which the following is a specification.

This invention relates to a construction of 1am-p socket by which the turning of the lamp will move it longitudinally and thus focus it with respect to the stationary inirror with which the lamp is used.

The principal objects of the invention are to simplify the arrangement for accomplish ing this result so as to reduce the number of pieces employed and cheapen the construction and assemblage of tie parts.

Reference is to be had to the accompanyingdrawings in which, Figiirev 1 isan elevation o a lamp socket constructed 'in accordance with this invention; Fig. 2 is a similar vier,1 of the opposite side thereof zal with parts broken away to show interior; construction; Fig. 3 is an elevation ofv a modification; and Fig. 4 is a view of the other side of 'the saine with parts broken away to show interior construction.

In the form shown in l-figil and2, the outer sleeve l0 is provided 'with a projeo tion 11 surroundingit, against which the mirror 12 is held. These parts are intended to. be fixedin the lamp casing so that they are stationary. .Thesleeve is provided with a helical slot-13 on one side and with spring tongue 14 on the other. This tongue. .informed simplyl by slitting the metal lonat tj'vo separated points, the tongue comingA between them. The tongue is corrugated. en both surfaces.

nside the sleeve is a cylindrical bushing y16 `for receiving the` hard rubber plug il'.

l presses againsta slotted head 2l on the rod' insidey the plug is a screw threaded rod i8 which has a terminal 19 tor the wire., i:

y,spring 2() entering a socket in the plug 17 and firmly forces this out toward the lamp Z2 which is designed to be inserted in the end of this bushing in the usual way and haveits terminal engage a metallic ro'ection extending inwardly from the head 2l.

The bushing i6 is formed from a section of comparatively "thin metal tubing and has a helically arranged series of corrugations on one flat surface thereof.

upon its outer surface as clearly shown' in Fig. l.

The bushing 16 is also provided with a lug 23 integral therewith or secured thereto, said lug being adaptedto enter and co operate with the helical slot 13 to relatively position the sleeve 10 and bushing 16 longitudinally.

The slit at the left hand'side of the tongue 14 is extended obliquely downwardly so as to permit that portion of the sleeve 10 which borders the upper end of theslot 13 to be sprung outwardly to permit the lug 23 to be inserted in the slot 13.

In operation it will be understood that the sleeve 10 is held in stationary position in the lamp frame and that the lamp itself is introduced into the end of the bushing in the usual way. The turning of the lamp lamp in any adjusted position.

In the form shown in Figs. 3 and 4, similar results are secured, but the mechanism is notso simple to make and assemble. In this case there is an outer sleeve BOhaving a surrounding projection Slat one end for thc Thissleeve. isl providud with a helical groove 33.A It is also powided with a longitudinal groovef. Inside the sleeve is a bushing 36 for receiving the insulating plug 37 and this has a conducting rod there- Yiiiconnected with the terminal 39 in a manner similar to that shown in FigEvQI.; The ring 44 has projection 38 for guiding it along theslot 34.

The lamp isheld in the end of the bushiiig in the same way as shown in Fig. 2. On the outside of the hardriibber insulating plug is fixed a ring "40 having ratchet teeth This ring is provided with a screw 43 entering the slot 33 so that the turning of the lamp will result in moving it longitudinally, as in'theother case. The second member` oftheratgoliet .flevice comprises a second ring 44jhaving teeth adapted to engage the teeth of4 the ring '40, and a spring 45 is provided between thisr;

Slt

ring and the edge of the projection 31 so'as to hold the ratchet members together. .The operation of the adjustment will be obvious.

Although We have shown and described only two forms of the invention, We are aware of the fact that other modifications can be made hy any person skilled in the art without departing from the Scope of the invention as expressed bythe claims. Therefore, We do not wish to ne limited to the particular constructions shown, butlVhat We do claim isf- 1. In an adjusting and focusing device for un electric lamp, the combination of a cylindrical sleeve having n helical groove therein, n bushing inside the sleeve adapted to move therein, said bushing having a `eircumferential ratchet thereon`V :1 projection extending from seid bushing into Suid slot, Whereh)1 the turning' of the bushing Will move .the same longitudinally, and :1 Second ratchet member engaging the ratchetmember of the bushing and connected with the sleeve.

2, in e focusing nd adjusting device for an electric lamp', the combination of a sleeve having a? helicnl slot in the cylindrical portion thereof, and' abushing movable therein provided with `longitudinal external corrugations thereon and having n projection ex tending into said slot for causing the bushing to move longitudinally when turned,

said sleeve being provided with a resilient tongue having longitudinal corrugations thereon for .engaging the corrugated surface of the bushing find veonsitituzting a ratchet.

In testimony whereof we have hereunto set our hands, in the presence .of two s11hstribing Witnesses.

HARRY H. HOLLAND.

JASON C. STEARNS.

Witnesses: I

CHAS. H. Pinon, IGEQ. H. STEARNS. 

